40 series cvt help please

[Chevyloonatik]

So ive got a carter brothers mini monster, ive got a 15hp 420cc motor with a 40 series clutch. 703985 belt, red spring in the driven 7 inch, 14 tooth #40 sprocket to a 20 tooth jack shaft then 12 tooth out to 54 tooth at wheel, tire size is 22 inch. Im 190 lbs and the cart is probably around 300lbs. Im having belt issues, i had a newer belt that did some light break inbefore going out for a ride. The belt made it for half the day of riding before it wore down to barely moving. The motor is new and the clutches are new as well. The driven is floating on its shaft so it can keep proper alignment at all times. Anyone have issues like this? Im ready to cut my losses on the motor and drive system in place of a quad motor with gears because belts here in canada are 60 bucks each and i dont want to pay that everytime i take it out

 

[Budget GoKart]

It might be your gearing. belts shouldnt do that

 

[itsid]

gear ratio is on the edge but should work if all your numbers are correct.

BUT the red spring on a 40 series TC is the stock spring.
Which means the driver is to be mounted inboard.
And driver and driven open in the same direction so no need to have it floating.

I assume you have the driven mounted outboard (since you said it's floating to keep the belt aligned)
in that case you need the reverse wound spring which is the yellow one.

Also: 15 horse 420 ? I know 13 horse 420s; 15 I cannot remember seeing.
And that ratio with just 13 horses is a bit sketchy...
a tooth more on the axle wouldn't harm let's say

'sid

 

[LawnCrawler]

Can you please elaborate on the stock spring facing inboard?
I understand what you are saying, but why does the red spring inboard while others presumably sit outboard. Mine has a yellow spring, is mounted outboard and seems to work perfectly.

Thanks

 

[Chevyloonatik]

gear ratio is on the edge but should work if all your numbers are correct.

BUT the red spring on a 40 series TC is the stock spring.
Which means the driver is to be mounted inboard.
And driver and driven open in the same direction so no need to have it floating.

I assume you have the driven mounted outboard (since you said it's floating to keep the belt aligned)
in that case you need the reverse wound spring which is the yellow one.

Also: 15 horse 420 ? I know 13 horse 420s; 15 I cannot remember seeing.
And that ratio with just 13 horses is a bit sketchy...
a tooth more on the axle wouldn't harm let's say

'sid

Thanks for the response, yes its a 420 15hp motor, im in canada and the 420 is either a 13 or 15 depending on what you buy, the 15 is a bit more at the till. I had a 26 in place of the 20 on the jack shaft and it was so slow i could have ran faster. The machine originally had a 6hp with tav2 on it and would go 50 kmh on flat land, the way this thing is now i can barely hit 50kmh on flat land but it will climb along the local trails better. I just want a happy medium where im not eating belts to go riding but able to go riding and not be so slow that itd be better off jogging. The 6hp had 12 tooth off the driven to 36 on the jack shaft but was a 30 series chain i believe

 

[itsid]

Can you please elaborate on the stock spring facing inboard?
I understand what you are saying, but why does the red spring inboard while others presumably sit outboard. Mine has a yellow spring, is mounted outboard and seems to work perfectly.

Thanks

Most mistake people make is the assumption that a TC is a TC is a TC.
series 30 for example also have red, green and yellow springs.
but the driven MUST ALWAYS run outboard (cam portion pointing away from the engine)
series 20 and series 40 are of completely different bred
they usually run inboard and in case you need to run it outboard,
you will need a reverse wound spring in order to distinguish a spring on the shelf easily.
they're color coded by the mfg.
(Comet uses red and green for inboard springs and yellow for outboard springs on series 20 and 40 TCs)
chinese mfgs might have used different colors in the past, but with much troubles every now and again so most switched to comet's color scheme of things.
If you see a red spring on an outboard mounted series 40 driven..
99% of the time it's just not working!
(most famous: GPS's first images of the series 40 backplate setup)
More recently, some sellers on ebay flipped the driver inboard and had the driven facing outboard.
In such cases the red spring is of course the correct one.

Thanks for the response, yes its a 420 15hp motor, im in canada and the 420 is either a 13 or 15 depending on what you buy, the 15 is a bit more at the till. I had a 26 in place of the 20 on the jack shaft and it was so slow i could have ran faster. The machine originally had a 6hp with tav2 on it and would go 50 kmh on flat land, the way this thing is now i can barely hit 50kmh on flat land but it will climb along the local trails better. I just want a happy medium where im not eating belts to go riding but able to go riding and not be so slow that itd be better off jogging. The 6hp had 12 tooth off the driven to 36 on the jack shaft but was a 30 series chain i believe

sure it's slow

with the driven being mounted incorrectly (outboard running a red spring, inboard with a yellow spring)
it's NOT able to shift, thus you stay in lowest gear at all times
eating away all rubber parts (belt and buttons)
one day it'll snap the buttons and will no longer move at all.

Post pics since I always assume a correctly outboard mounted driver for historical reasons
you might not..
with pics that'd all be solved.


'sid

 

[LawnCrawler]

thanks for the explanation. I had to read that about four times, but it makes sense

 

[Chevyloonatik]

Most mistake people make is the assumption that a TC is a TC is a TC.
series 30 for example also have red, green and yellow springs.
but the driven MUST ALWAYS run outboard (cam portion pointing away from the engine)
series 20 and series 40 are of completely different bred
they usually run inboard and in case you need to run it outboard,
you will need a reverse wound spring in order to distinguish a spring on the shelf easily.
they're color coded by the mfg.
(Comet uses red and green for inboard springs and yellow for outboard springs on series 20 and 40 TCs)
chinese mfgs might have used different colors in the past, but with much troubles every now and again so most switched to comet's color scheme of things.
If you see a red spring on an outboard mounted series 40 driven..
99% of the time it's just not working!
(most famous: GPS's first images of the series 40 backplate setup)
More recently, some sellers on ebay flipped the driver inboard and had the driven facing outboard.
In such cases the red spring is of course the correct one.


sure it's slow

with the driven being mounted incorrectly (outboard running a red spring, inboard with a yellow spring)
it's NOT able to shift, thus you stay in lowest gear at all times
eating away all rubber parts (belt and buttons)
one day it'll snap the buttons and will no longer move at all.

Post pics since I always assume a correctly outboard mounted driver for historical reasons
you might not..
with pics that'd all be solved.


'sid

I have the direction of the driven going the correct rotation for the red spring. Learned the hard way the first time i got it going. My top speed is about 40 kmh before the brlt starts to go crappy, it is a chinese ebay 40 series that is brand new

 

[itsid]

I have the direction of the driven going the correct rotation for the red spring. Learned the hard way the first time i got it going. My top speed is about 40 kmh before the brlt starts to go crappy, it is a chinese ebay 40 series that is brand new

direction of the driven is the way it rotates (the way it was preloaded)
I assume you mean orientation (the way it's mounted)
to be correct for the red spring, right?
so just to be clear:
your driven is oriented opposite to the driver's nut
like so


In that case the driven shouldn't float at all..
but rigidly mounted in line with the driver.

Now belt... I don't know any Comet 703985 belt
(and I cannot find one on google either)
Comet belts start with 203, 204 or 213 for the comet series 40
carter belt part numbers are (G###) so it's not that either.

Since I don't know your center to center distance I can't tell what
exact number you should be looking for.
measure how far apart the centers of each shaft are spaced
(crankshaft to jackshaft)
with that we can determine the belt you need.

And finally, what model exactly is the mini monster you have?
is it 1805, 1815, 1825 ... 1875, 1885... ??
you have a geared down chain drive steering ?

Know what this is really tedious.. post a few pics of your kart,
and a few of the TC installed, and we can get that information from those much quicker

'sid

 

[Chevyloonatik]

direction of the driven is the way it rotates (the way it was preloaded)
I assume you mean orientation (the way it's mounted)
to be correct for the red spring, right?
so just to be clear:
your driven is oriented opposite to the driver's nut
like so
View attachment 113593

In that case the driven shouldn't float at all..
but rigidly mounted in line with the driver.

Now belt... I don't know any Comet 703985 belt
(and I cannot find one on google either)
Comet belts start with 203, 204 or 213 for the comet series 40
carter belt part numbers are (G###) so it's not that either.

Since I don't know your center to center distance I can't tell what
exact number you should be looking for.
measure how far apart the centers of each shaft are spaced
(crankshaft to jackshaft)
with that we can determine the belt you need.

And finally, what model exactly is the mini monster you have?
is it 1805, 1815, 1825 ... 1875, 1885... ??
you have a geared down chain drive steering ?

Know what this is really tedious.. post a few pics of your kart,
and a few of the TC installed, and we can get that information from those much quicker

'sid

Sorry typo on the belt number, its 203785. Center to center distance of 8 3/16 for the shafts. I cant figure out how to load pics of it. I am using the cheaper belts and not the true comet belts as those are super expensive here and i dont want to risk blowing one of those as quick as these get eaten up. Im probably cutting my losses and putting an atv motor in with gears instead.

 

[itsid]

cheaper belts might be cheap for a reason I'm afraid..
many before you found that a 30 dollar belt lasting twice as long as a 20 dollar belt still saves you ten bucks

but let's solve one issue at a time

uploading images is easy:
click on the blue pill shaped "Post reply" button
and use the paperclip from the toolbar
or look at the detailed description on how to post pics

top group allows you to upload pics from your device/computer
bottom group allows you to upload from a third party website

'sid

 

[Chevyloonatik]

Heres a pic i hope of the motor and clutches installed. If this works ill get a better pic and load it

 

[itsid]

going by that pic
(have you smeared grease over the phone lens first )
it looks like your belt is crooked, which would indeed explain some of the additional wear.

make sure the belt runs perfectly perpendicular to the engine and jack shaft.

Also it definetely looks like you have the driven the wrong way around for the red spring.
(going by what little we can see of the driven)
since your driver is facing the wrong way.. the driven must face the wrong way too
for the stock spring to work.

Sooo yeah that's the other half of ruining your belt (and buttons in the long run)

'sid

flip the driver to correct orientation, align the belt and you will be fine I guess.

 

[Budget GoKart]

going by that pic
(have you smeared grease over the phone lens first )

I don't know if it's grease it kinda looks like he used a Nokia to take that picture honestly

 

[Chevyloonatik]

direction of the driven is the way it rotates (the way it was preloaded)
I assume you mean orientation (the way it's mounted)
to be correct for the red spring, right?
so just to be clear:
your driven is oriented opposite to the driver's nut
like so
View attachment 113593

In that case the driven shouldn't float at all..
but rigidly mounted in line with the driver.

Now belt... I don't know any Comet 703985 belt
(and I cannot find one on google either)
Comet belts start with 203, 204 or 213 for the comet series 40
carter belt part numbers are (G###) so it's not that either.

Since I don't know your center to center distance I can't tell what
exact number you should be looking for.
measure how far apart the centers of each shaft are spaced
(crankshaft to jackshaft)
with that we can determine the belt you need.

And finally, what model exactly is the mini monster you have?
is it 1805, 1815, 1825 ... 1875, 1885... ??
you have a geared down chain drive steering ?

Know what this is really tedious.. post a few pics of your kart,
and a few of the TC installed, and we can get that information from those much quicker

'sid

This is it after sitting outside a few days, i see the motor has come slightly out of alignment

My camera lens is broken on my phone hence crappy pictures

---------- Post added at 10:26 PM ---------- Previous post was at 10:16 PM ----------

Now if i flip the driven and driver over what do i do about the driven set up for the rotation being opposite way?

 

[itsid]

Now if i flip the driven and driver over what do i do about the driven set up for the rotation being opposite way?

NO!
you flip ONE around not both!
in your case the DRIVER
the nut of the driver must face in the OPPOSITE direction of the cam on the driven
look at the diagram I posted above!!

'sid